Fluid stripper for pump pistons



Feb. 1, 1944. Q T s 2,340,471

FLUID STRIPPER FOR PUMP PISTONS Original Filed Nov. 17, 1938 INVENTUR 49 yfb zzzzszp g K A TTORNE )5.

Patented Feb. 1, 1944 aiipiic a iinv hi r 17, 1938, seen ,39z,;1iow Paten-t No. 2,256, 1151511 September 23, 1941. Divided anilthis application August 2; 1941, Serial No. 405,138

2 tines. (01. 286-28) This inventihn relates t fire extinguisher r the hand type and isja division and continuation in part of applicants co- -pen 'i ing United States applications, Serial No; 240,892 and Serial 'No. 350,681, filed November 17, 1938,- and August 3, 1940, respectively, now matured as Patents No. 2,256,902 and No. 2,326,861, issued September 23, 194i, and August 17,1943,- respectively. v

The main objects of this inventionare to provide a fire extinguisher which is assured of bjeing in operable condition regardless of the length of time of non use and which, therefore, can be depended upon ata'll timesin theevent of emergency; to provide iniprovedmeans for stripping the fluid from the' piston rod so as to prevent slight leakage or dripping when the rod is reciprocated through its packing gaskets and which means is resilient andyieldin'g so as to not becoine frozen on the red by corrosion during long periods of non-use. c I c I An illustrative embodimentof this invention is shown in the accompanyingfdrawing, in which:

Fig; 1 is an enlarged,fragmentary, medial sectional view of the improved fire extinguisher showingthe details oi construction of the piston rod packing'glalnds and sealing means; r n

Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1; and

, Fig. 3 is an enlarged iragmentary side le'va tion of the axially slidable sleeve as viewed irom the line 3-4 oi Fig'. l; showing a portion of the cylindrical sleeve of' the lower extension of the handle and showing a portion of the cap and flange portions thereof in broken lines; g V

The important problem oi the fire extinguisher manufacturer is to make an apparatus which is leak-proof'when the" extinguisher is not in use and at the sametime'ha've an extinguisher which unquestionably will operate im'mediately when an emergency or fire arises; It is, of course, selfevident that a fire extinguisher from which the fire extinguishingffluid has leaked or evaporated out or a fire extinguisher in which the working parts are frozen and will not operate in case of an emergency are both worse th'an'having' no fire extinguisher at all g A problem encountered in the use of fire exting'uisher's having felt packing glands for the piston rod has been that of the fluid adherin'g to the piston rod as it is drawn through the gaskets and then drippingoff; in the hands of the user during thep'umpingstrokes. I H

In the present invention, {this objection has been overcome by ha ing thehelic'al compression spring, which compresses the rod gaskets; fit

nular se'alin'g ,i'nemb'er l6 and piston rod' spaced relation thereto and the upperend is prophiiits attire cotter area h assure tightly around the rod, so that it act'sjas ,a resiliently. gripping fluid.v stripper. Due to., .th e yieldability of the spring, it may. have a snug fit around the rod, but will not freeze. thereto by eorrosion. i

In the construction shown in the drawing, a cylindrical reservoir 5 has the usualpumping and valve mechanisms contained therein. .5

The upper end of the reservoir is closed by a cap 9 brazed or otherwise sealed thereto in which is a filler opening with screw. closure plug, ,not shown, in the usual manner offire extinguishers of this character. The cap Slhas an annular 'ing fit with a piston rod! 4. which is slidable therethrough. The outer axial face of thesleeve it forms a sealing face, l3 whichcoacts withan annular ring gasket l5. carried by. an annular sealing member it which is rigidly brazedor otherwise secured to the piston rod 54. .The member, it comprises an, axially. extending cylindrical skirt portion I! which embraces andcarries' the gasket 15, and an oppositely extending cylindrical sleeve portion 18., the axial end of which terminatesiin an exteriorly threaded lend I9. A handle 20, having an: axially extending hollow shank 2i, isthreaded on the end 19 in abutting relationship against a shoulder of the sleeve It, to limit and positiontheparts;

An axially slidable sleeve 22 surrounds, the anvided with a radially disposed, inwardly extending flange which is freely slidable on the sleeve portion it of the annular sealing members; A helical compression spring 24 is, provided in the space between the 'fixd sleeve ll 8 and the slidable sleeve "22 and loears between the seaiinginniber 1c and the flange 23 or the sleeve '22; a

The lower-end of the sli'dalol'e'sleeve 22 is pro- 'vided with diametrically opposed radially extending lugs 25 and 26', eachhaving' two cam surfaces on their outer axiai'r aces; The two we surfaces on each me have reverse slopes fo'rinihghigh H hs 5 35 e 3. 9!. se. lu 28 integrally H d id hi i meagre-an li g 9P3. Said openings-'IOI and H12 are, prefers.

I A. Us: .v to provide relatlvely sharp corners which enga contact, will have a the cam surfaces of the lugs 25 and 26 as shown out to provide a cylindrical sleeve 3| which sur rounds the axially slidable sleeve 22 and which is provided with diametrically opposed axially extending inwardly presenting slots 32 and 33 which receive similarly disposed ribs 34 and 35, respectively, which are integrally formed on the slidable sleeve 22 wherebythe sleeve and handle are non-rotatably secured while permitting relative axial movement therebetween.

The hollow shank 2| of the handle 2|] is provided with an axially extending bore 36 in which is housed a helical compression spring 31, one

end of which abuts the blind end of the bore 36 and the other end of which contacts an axially slidable floating seal 38, the inner face of which fits upon and closes one end of a discharge tube 40 when the handle is in closed position, as shown in Fig. 1.

The inner end of the sleeve I2 is interiorly threaded to receive the exteriorly threaded axially extending sleeve portion 4I of a fitting 42 which is provided with an oppositely extending cylindrical sleeve portion 43 which has a free The space be tween the piston rod I4 and the sleeves I2 and 4| is provided at its upper end with a felt gasket sliding fit on the piston rod I4.

44, a. cork washer I45, and a brass washer 45 bearing thereagainst. The gasket 44 is constantly urged in compression around the piston rod I4 by a helical compression spring 46, which 7 snugly surrounds and yieldingly grips the rod .I4, so as to strip the fire extinguishing fluid from the rod during reciprocation thereof. One end ofthe compression spring 46 bears against the against a similar but smaller washer 41 which fits against a felt gasket ring 48 disposed at the .other end of the space, thus providing a double yielding seal around the piston rod which is automatically tensioned at. all times and which pre- .vents substantial leakage of fluid around the piston rod during its reciprocation when subjected to pumping action. I.

.The piston rod I4 is surrounded by apumping cylinder 49, one end of which is fixed to a rotatable head 50 andthe other end of which is similarly fixed in a similar rotatable head (not shown).

The head 59 which supports the upper end of e the pumping cylinder 49 is provided with a felt packing ring or gasket 64 which is retained by a relatively thin brass washer 65 secured on an annular radially extending seat by rolling over the metal at the edge of the opening which receives the washer, as shown at 66. The inner edge of the washer 65 rides upon the outer surface of the axially extending sleeve portion 43 which serves as a bearing for supporting the upper end of the suction mechanism and which bearing, having relatively small metal to metal minimum of tendency to stick and present very little friction to rotation of the head, thus providing a structure which will have freedom from freezing by reason of 'corrosion or the like.

The head 50 is provided with a laterally extending weighted arm having passageways therethrough with ball check valves which serve as suction ports for the pumping cylinder. The upper end of the cylinder 49 communicates with a radially extending port 61 controlled by ball valve 68 which leads to an axially extending passageway 69, one end? of which is controlled by a ball'check valve I0 and which in turn communicates with a second radially extending port II, the outer open end of which lies closely adjacent to the inner peripheral wall of the reservoir 5. The end of the passageway 69 opposite to the ball check valve Ill communicates with an washer and the other end thereof bears axially extending tube I2, the upper end of which is rigidly secured in axial alignment therewith.

A detailed description and illustration of the complete mechanism is shown in my aboveidentifled patents.

A metal rod 16 is housed within the tube 12 and functions to tap the ball check valve ID off of its seat when the fire extinguisher is'inclined upwardly, thus insuring free communication for the passage of fluid from the reservoir into the tube I2 and head50. V

In the operation of this fire extinguisher, the reservoir 5 is filled with fire extinguishing fluid through an opening in the head 9 (not shown) in the usual manner. During non-use of the fire extinguisher the cam lugs 25 and 26 are engaged under the inturned flanges 21 and 28, thus compressing the helical spring 24 between the radially extending inturned flange 23 and the annular sealing member I6 which is brazed to the piston rod I4, thus compressing the gasket I5 between the sealing member I6 and the outer axial face I3 of the sleeve II. Thus a fluid tight effective seal is maintained at all times which will prevent leakage or evaporation of the fluid within the reservoir past or through the opening in the sleeve II around the piston rod I4.

When the handle is in the foregoing described closed and sealed position, the lower face 39 of the floating seal 38 is'tightly pressed against the upper end of discharge tube 40 by the helical compression spring 31, thus preventing any leakage or evaporation of fluid through'the discharge tube 40 and nozzle opening 8 of the apparatus.

When it is desired to operate the fire extinguisher, the reservoir portion 5 is grasped in one hand, the handle 20 in the other, and the handle rotated relatively to the reservoir, in either direction, until the cam lugs 25 and 26 spring from under the flange portions 21 and 28, at which time the handle is free to move axially.

During the upward stroke of the piston, the fluid which is in the pumping cylinder 49 is prevented from passing out around the piston rod I4 through the head 50 by reason of the stripping action of the spring 46, and the resilient felt packing rings 44, 48 and 64. 7

It will also be equally evident that when the handle 29 is forced downwardly so as to compress the spring 31, the floating seal 38 will effectively close the upper end of the discharge tube 40 and prevent evaporation or leakage of the fluid thereinto. When the cam lugs 25 and 26 are rotated underneath the flanges 21 and 28, the sliding sleeve 22 will move axially downwardly toward the head 9, as shown in Fig. 1 of the drawing, thus compressing the spring 24 which yieldingly holds the annular'sealing member I6 and gasket I5 tightly upon the sealing face I3 of the sleeve member II.

The cylindrical sleeve pardon I2 is provided with a plurality of axially extending slots or notches 90 through which the fluid that is stripped from the piston rod l4 may return to the interior of the reservoir.

What is claimed is:

1. In a piston rod packing, a compressible, annular packing adapted to surround and snugly fit the rod and a helical spring having spaced convolutions with a normal interior diameter slightly less than the exterior diameter of the rod and adapted and arranged to yieldingly embrace the rod for stripping fluid therefrom during reciprocation thereof, said spring having free ends and exerting a yielding axial pressure on 5 to surround and snugly fit the rod and a helical spring having spaced convolutions with a normal interior diameter slightly less than the exterior diameter of the rod and adapted and arranged to yieldingly embrace the rod for stripping fluid 10 therefrom during reciprocation thereof, said spring having free ends and exerting a yielding axial pressure on said packings for compressing said packings around the rod.

CHARLES K. HUTHSING. 

